Catheter Control Systems

ABSTRACT

A medical manipulation assembly comprises an elongated distal steerable portion with a distal working channel extending through the elongated distal steerable portion. The assembly also comprises an elongated proximal steerable portion arranged proximally of the elongated distal assembly portion. A proximal working channel extends through the elongated proximal steerable portion. The assembly also comprises a distal steering mechanism to bend the distal steerable portion in response to movement of the distal steering mechanism. The assembly also comprises a proximal steering mechanism to bend the proximal steerable portion, independently of the distal steerable portion, in response to rotational movement of the proximal steering mechanism. The assembly also comprises distal pullwire(s) extending between the elongated distal steerable portion and the distal steering mechanism and proximal pullwire(s) extending between the elongated proximal steerable portion and the proximal steering mechanism. The distal and proximal portion working channels are configured to receive a visualization instrument.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Prov. Pat. App.61/078,746 filed Jul. 7, 2008, which is incorporated herein by referencein its entirety.

FIELD OF THE INVENTION

The present invention relates generally to catheter control systems forcontrolling the articulation of visualization and treatment apparatushaving imaging and manipulation features for intravascularly accessingregions of the body.

BACKGROUND OF THE INVENTION

Conventional devices for accessing and visualizing interior regions of abody lumen are known. For example, various catheter devices aretypically advanced within a patient's body, e.g., intravascularly, andadvanced into a desirable position within the body. Other conventionalmethods have utilized catheters or probes having position sensorsdeployed within the body lumen, such as the interior of a cardiacchamber. These types of positional sensors are typically used todetermine the movement of a cardiac tissue surface or the electricalactivity within the cardiac tissue. When a sufficient number of pointshave been sampled by the sensors, a “map” of the cardiac tissue may begenerated.

Another conventional device utilizes an inflatable balloon which istypically introduced intravascularly in a deflated state and theninflated against the tissue region to be examined. Imaging is typicallyaccomplished by an optical fiber or other apparatus such as electronicchips for viewing the tissue through the membrane(s) of the inflatedballoon. Moreover, the balloon must generally be inflated for imaging.Other conventional balloons utilize a cavity or depression formed at adistal end of the inflated balloon. This cavity or depression is pressedagainst the tissue to be examined and is flushed with a clear fluid toprovide a clear pathway through the blood.

However, many of the conventional catheter imaging systems lack thecapability to provide therapeutic treatments or are difficult tomanipulate in providing effective therapies. For instance, the treatmentin a patient's heart for atrial fibrillation is generally made difficultby a number of factors, such as visualization of the target tissue,access to the target tissue, and instrument articulation and management,amongst others.

Conventional catheter techniques and devices, for example such as thosedescribed in U.S. Pat. Nos. 5,895,417; 5,941,845; and 6,129,724, used onthe epicardial surface of the heart may be difficult in assuring atransmural lesion or complete blockage of electrical signals. Inaddition, current devices may have difficulty dealing with varyingthickness of tissue through which a transmural lesion is desired.

Conventional accompanying imaging devices, such as fluoroscopy, areunable to detect perpendicular electrode orientation, catheter movementduring the cardiac cycle, and image catheter position throughout lesionformation. The absence of real-time visualization also poses the risk ofincorrect placement and ablation of structures such as sinus node tissuewhich can lead to fatal consequences.

Moreover, because of the tortuous nature of intravascular access,devices or mechanisms at the distal end of a catheter positioned withinthe patient's body, e.g., within a chamber of the heart, are typicallyno longer aligned with the handle. Steering or manipulation of thedistal end of the catheter via control or articulation mechanisms on thehandle is easily disorienting to the user as manipulation of a controlon the handle in a first direction may articulate the catheter distalend in an unexpected direction depending upon the resulting catheterconfiguration leaving the user to adjust accordingly. However, thisresults in reduced efficiency and longer procedure times as well asincreased risks to the patient. Accordingly, there is a need forimproved catheter control systems which facilitate the manipulation andarticulation of a catheter.

BRIEF SUMMARY OF THE INVENTION

A tissue imaging and manipulation apparatus that may be utilized forprocedures within a body lumen, such as the heart, in whichvisualization of the surrounding tissue is made difficult, if notimpossible, by medium contained within the lumen such as blood, isdescribed below. Generally, such a tissue imaging and manipulationapparatus comprises an optional delivery catheter or sheath throughwhich a deployment catheter and imaging hood may be advanced forplacement against or adjacent to the tissue to be imaged.

The deployment catheter may define a fluid delivery lumen therethroughas well as an imaging lumen within which an optical imaging fiber orassembly may be disposed for imaging tissue. When deployed, the imaginghood may be expanded into any number of shapes, e.g., cylindrical,conical as shown, semi-spherical, etc., provided that an open area orfield is defined by the imaging hood. The open area is the area withinwhich the tissue region of interest may be imaged. The imaging hood mayalso define an atraumatic contact lip or edge for placement or abutmentagainst the tissue region of interest. Moreover, the distal end of thedeployment catheter or separate manipulatable catheters may bearticulated through various controlling mechanisms such as push-pullwires manually or via computer control

The deployment catheter may also be stabilized relative to the tissuesurface through various methods. For instance, inflatable stabilizingballoons positioned along a length of the catheter may be utilized, ortissue engagement anchors may be passed through or along the deploymentcatheter for temporary engagement of the underlying tissue.

In operation, after the imaging hood has been deployed, fluid may bepumped at a positive pressure through the fluid delivery lumen until thefluid fills the open area completely and displaces any blood from withinthe open area. The fluid may comprise any biocompatible fluid, e.g.,saline, water, plasma, Fluorinert™, etc., which is sufficientlytransparent to allow for relatively undistorted visualization throughthe fluid. The fluid may be pumped continuously or intermittently toallow for image capture by an optional processor which may be incommunication with the assembly.

In an exemplary variation for imaging tissue surfaces within a heartchamber containing blood, the tissue imaging and treatment system maygenerally comprise a catheter body having a lumen defined therethrough,a visualization element disposed adjacent the catheter body, thevisualization element having a field of view, a transparent fluid sourcein fluid communication with the lumen, and a barrier or membraneextendable from the catheter body to localize, between the visualizationelement and the field of view, displacement of blood by transparentfluid that flows from the lumen, and an instrument translatable throughthe displaced blood for performing any number of treatments upon thetissue surface within the field of view. The imaging hood may be formedinto any number of configurations and the imaging assembly may also beutilized with any number of therapeutic tools which may be deployedthrough the deployment catheter.

More particularly in certain variations, the tissue visualization systemmay comprise components including the imaging hood, where the hood mayfurther include a membrane having a main aperture and additionaloptional openings disposed over the distal end of the hood. Anintroducer sheath or the deployment catheter upon which the imaging hoodis disposed may further comprise a steerable segment made of multipleadjacent links which are pivotably connected to one another and whichmay be articulated within a single plane or multiple planes. Thedeployment catheter itself may be comprised of a multiple lumenextrusion, such as a four-lumen catheter extrusion, which is reinforcedwith braided stainless steel fibers to provide structural support. Theproximal end of the catheter may be coupled to a handle for manipulationand articulation of the system.

To provide visualization, an imaging element such as a fiberscope orelectronic imager such as a solid state camera, e.g., CCD or CMOS, maybe mounted, e.g., on a shape memory wire, and positioned within or alongthe hood interior. A fluid reservoir and/or pump (e.g., syringe,pressurized intravenous bag, etc.) may be fluidly coupled to theproximal end of the catheter to hold the translucent fluid such assaline or contrast medium as well as for providing the pressure toinject the fluid into the imaging hood.

One example of a system configured to enable direct visualization oftissue underlying the hood and optionally treat tissue, e.g., ablation,may include an ablation assembly, hood, and deployment catheter coupledto a handle having a catheter steering and locking assembly integratedalong the handle. The catheter steering and locking assembly may includea steering member pivotably coupled to a locking member where thesteering member may be coupled to one or more pullwires attached theretovia a retaining member, e.g., set screw, such that manipulation of thesteering member articulates the steerable section and hood in acorresponding manner. The steering member may be pivotably coupled tothe locking member along a point of rotation and locking mechanism whichis attached to a steering plate.

The catheter shaft contains at least one lumen which allows the passageof one or more pullwires that are connected to the steering member atthe proximal end of the pullwire while the distal end may be terminatedand anchored to the steering mechanisms along the steerable portion ofthe catheter. A compression coil, e.g., made of stainless steel, with aslightly larger diameter than the pullwire may be positioned about thepullwire within the handle to allow the pullwire to slide freelytherethrough.

In use, the steering member may be actuated, e.g., by pulling the memberproximally, to articulate the steerable portion and hood in the samedirection of articulation. With the steerable portion articulated to thedegree desired to position the hood, the locking member may be actuatedto maintain a configuration of the steerable portion and hood bypreventing or inhibiting movement of the steering member thus freeingthe hand or hands of the user. A steering indicator and/or lockingindicator may be optionally incorporated along the handle as a reminderto the user.

The handle assembly may also optionally incorporate an opticaladjustment assembly which may be used to move the distal lens of avisualization instrument, such as a fiberscope, distally or proximallyfrom the imaged tissue region, hence simulating a zoom-in and/orzoom-out optical effect. Generally, the optical adjustment assembly isable to provide zoom-in and/or zoom-out capabilities by varying thelength of the assembly. By rotating an adjustment member, which iscoupled to a retaining sleeve within the optical adjustment assembly, adistal shaft portion may be advanced or retracted relative to the guideshaft. The assembly may be accordingly varied in length while distallyor proximally advancing the fiberscope based on the varied length of theoptical adjustment assembly to control the visualized field of view.

Because manipulation of the hood and steerable portion corresponds withan angle at which the handle is positioned, the handle may also serve asan orientation indicator for the hood and steerable portion once thehood has been introduced into the patient's body. This correspondencebetween the planes of the handle and the resulting articulation of thehood and steerable-portion may be particularly useful for efficientlycontrolling the hood position within the patient's body. As the catheteris usually repeatedly torqued during a procedure, keeping track of theorientation of the deflection of the hood can be difficult, if notimpossible, unless fluoroscopy is used. With the handle, the angle ofdeflection of the hood can be predicted by the operator without the needof fluoroscopy. This is can be particularly desirable in procedures suchas transseptal punctures where an accurate angle of puncture of theseptal wall is desirable to avoid complications such as perforation ofthe aorta.

Another variation of a steering handle assembly may include an assemblyhaving a handle portion and a steering ring which may be manipulatedalong any number of directions relative to the housing to control thearticulation of the hood. Manipulating or pulling along a portion of thesteering ring causes the steerable portion and hood to move along acorresponding direction of articulation. Moreover, because of the mannerin which the steering ring is positioned to encircle the handleassembly, the operator may grip the handle along any orientation andoperate the handle assembly with a single hand.

The handle assembly may generally comprise a ball pivot supported bypivot support enclosed within the housing. The ball pivot may supportthe steering ring via one or more steering ring support members, e.g.,four steering ring support members, which extend radially throughcorresponding support member openings. Because of the ball pivot shape,the steering ring may be moved about the pivot in any number ofdirections. The terminal ends of one or more pullwires may be coupledthe steering ring via corresponding fasteners, e.g., set screws,securing each of the pullwire termination crimps. These pullwires mayextend through the pivot support housing and through a pullwiretransition manifold and into a proximal end of a multi-lumen shaft, suchas the catheter. The pullwires may continue distally through thecatheter where they are coupled to the steerable portion of thecatheter. Each of the pullwires may be optionally encased incorresponding compression coils between the transition manifold andcatheter.

Although multiple pullwires may be utilized depending upon the number ofdirections for articulation, four pullwires may be typically utilized.Each of the four pullwires may be terminated symmetrically around acircumference of the steering ring such that a balanced four-waysteering of the distal portion may be accomplished, althoughmanipulating the steering ring along various portions of itscircumference may yield combinational articulation between the pullwiresto result in numerous catheter configurations. Additionally, the handleassembly may further incorporate a spring mechanism as an overdriveprevention mechanism positioned between the transition manifold and ballpivot in order to prevent over-tensioning or breaking of the pullwiresif the steering ring is over-deflected in a direction.

The handle assembly and catheter can be consistently deflected in thesame direction by which the steering ring is being deflected regardlessof the orientation of the handle assembly. For example, the handleassembly may be deflected in a first direction of actuation such thatthe hood is deflected in a corresponding first direction ofarticulation. If the handle assembly, catheter, and hood are thenrotated along an arbitrary direction of rotation about the longitudinalaxis of the assembly, even with the entire assembly rotated, e.g., 180°,actuating the steering ring along the first direction of actuation stillresults in a corresponding first direction of articulation of the hoodwhich matches the initial direction of articulation despite the rotatedassembly.

In yet another variation of the catheter control handle, the controlassembly may be configured to articulate at least two independentlydeflectable portions. As with previous variations, a steering ring mayencircle the housing. However, this variation further includes aproximal handle portion extending from the housing with a proximalsection control for articulating the proximal steerable section.Moreover, this particular handle assembly may be used to controlarticulation of the hood and the distal steerable section but also usedto further control articulation of the proximal steerable section. Aproximal section control located along the proximal handle portion maybe actuated, e.g., by rotating the control in a first and/or seconddirection, to articulate the proximal steerable section within a firstplane and the hood may be further articulated by manipulating thesteering ring such that distal steerable section moves in acorresponding direction of articulation.

Additionally and/or alternatively, visual indicators positioned directlyupon the hood may also be utilized in coordination with correspondingvisual indicators positioned upon the handle itself. The hood may haveone or more visual indicators marked upon the distal portion of the hoodsuch that the visual image through the hood may show at least a firstdirectional indicator along a first portion of the hood. The handleassembly may thus have one or more directional indicators locateddirectly upon, e.g., the steering ring, which correspond spatially withthe indicators positioned upon the hood or hood membrane.

The catheter control systems described herein may additionally integrateany number of features and controls for facilitate procedures. Thesefeatures and controls may be integrated into any of the variationsdescribed herein. One example may include features such as flow ratecontrol, air bubble detection, ablation activation switches, built-inimage sensors, etc., may be incorporated into the handle assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a side view of one variation of a tissue imaging apparatusduring deployment from a sheath or delivery catheter.

FIG. 1B shows the deployed tissue imaging apparatus of FIG. 1A having anoptionally expandable hood or sheath attached to an imaging and/ordiagnostic catheter.

FIG. 1C shows an end view of a deployed imaging apparatus.

FIGS. 2A and 2B show one example of a deployed tissue imager positionedagainst or adjacent to the tissue to be imaged and a flow of fluid, suchas saline, displacing blood from within the expandable hood.

FIGS. 3A and 3B show examples of various visualization imagers which maybe utilized within or along the imaging hood.

FIGS. 4A and 4B show perspective and end views, respectively, of animaging hood having at least one layer of a transparent elastomericmembrane over the distal opening of the hood.

FIGS. 5A and 5B show perspective and end views, respectively, of animaging hood which includes a membrane with an aperture definedtherethrough and a plurality of additional openings defined over themembrane surrounding the aperture.

FIG. 6 illustrates an assembly view of another example of avisualization system configured for a controlled articulation andmanipulation of the end effector.

FIG. 7A shows a side view of one example of a handle with access lumensand visualization instrumentation extending therefrom.

FIG. 7B shows a detail side view of an example of a steering and lockingmechanism located upon the handle.

FIGS. 8A and 8B show side views of an example of a visualization andtreatment catheter having a steerable distal end articulated by asteering member and locked into position.

FIG. 9 shows a perspective exploded assembly view of an example of thecatheter steering and locking assembly.

FIG. 10A shows a perspective exploded assembly view of an optionaloptical adjustment assembly which may be used to provide for zooming inand out of a visualization instrument, such as a fiberscope, through thecatheter.

FIGS. 10B and 10C illustrate cross-sectional side views of the opticaladjustment assembly showing the relative movement of the assembly toconvey the visualization instrument distally and proximally to adjustvisual images.

FIG. 11 shows a perspective view of an optional access cannula having astabilizing strain-relief wire for coupling to a handle.

FIG. 12 shows a side view of a handle assembly positioned to lie withina first plane correspondingly aligned with a second plane defined by adeflection of the steerable distal section.

FIGS. 13A and 13B show an example where a visualization hood has beenadvanced intravascularly within a patient's heart with a handlepositioned external to the patient and illustrates how re-orienting thehandle, e.g., by 90°, results in a corresponding articulation of theplane defined by the visualization hood and distal section within theheart.

FIG. 14 shows an assembly view of another variation of the handle whichis configured to manipulate the steerable distal section in multipledirections by a single hand of the user.

FIG. 15 shows a detail side view of the handle of FIG. 14.

FIG. 16 illustrates a single hand of the user manipulating amulti-directional steering ring located on the handle.

FIGS. 17A and 17B show cross-sectional side views of the handleillustrating the multiple pullwires attached to the steering ring.

FIGS. 18A to 18C show side views of the handle assembly illustrating howthe handle is configured to articulate and steer the visualization hoodconsistently in the same direction when urged by the steering ring inthe same direction regardless of the handle orientation.

FIG. 19 shows an assembly view of yet another variation of the handlewhich is configured to manipulate the steerable distal section inmultiple directions as well as curve yet another steerable sectionlocated proximal to the distal section.

FIGS. 20A and 20B show side views, respectively, of the catheter controlsystem handle.

FIGS. 21A and 21B show end views of the catheter control handle from theperspective of the catheter shaft and from the handle end, respectively.

FIGS. 22A and 22B show perspective assembly and detail views,respectively, of the visualization assembly and catheter control handle.

FIG. 23A shows a perspective view of a steerable proximal portion of thecatheter actuated by a proximal section control located along thehandle.

FIG. 23B shows a perspective view of the steerable distal portion of thecatheter further steered by actuation of the steering ring to maneuverthe visualization hood relative to the steerable proximal portion.

FIG. 24 shows a perspective exploded assembly view of the cathetercontrol handle.

FIG. 25 shows a cross-sectional side view of the catheter controlhandle.

FIG. 26 shows a cross-sectional detail side view of the catheter controlhandle having the pullwires in place for controlling both the distal andproximal portions.

FIGS. 27A and 27B show side views of die control handle undersingle-handed manipulation whether by a user's right hand or left hand,respectively.

FIG. 28 shows a perspective view of the control handle having anorientation guide located on the handle for reference to the user.

FIGS. 29A and 29B show another example where a visualization hood hasbeen advanced intravascularly within a patient's heart with the controlhandle positioned external to the patient and illustrates howre-orienting the handle, e.g., by 90°, results in a correspondingarticulation of the plane defined by the visualization hood and distalsection within the heart.

FIGS. 30A and 30B show an end view of the hood from the perspective ofan imager positioned within the hood and a side view of the controlhandle having orientation markers on the steering ring which correspondto similar orientation marks positioned along the hood.

FIG. 30C shows a perspective view illustrating how manipulation of thesteering ring in the direction of a particular marker results in acorresponding movement of the visualization hood in a direction ascorrelated to the marker indicated on the hood.

FIG. 31 shows an assembly view of yet another variation of the controlhandle incorporating multiple features.

FIG. 32 shows an assembly view of how an imaging system may beincorporated directly within the control handle.

DETAILED DESCRIPTION OF THE INVENTION

A tissue-imaging and manipulation apparatus described herein is able toprovide real-time images in vivo of tissue regions within a body lumensuch as a heart, which is filled with blood flowing dynamicallytherethrough and is also able to provide intravascular tools andinstallments for performing various procedures upon the imaged tissueregions. Such an apparatus may be utilized for many procedures, e.g.,facilitating transseptal access to the left atrium, cannulating thecoronary sinus, diagnosis of valve regurgitation/stenosis,valvuloplasty, atrial appendage closure, arrhythmogenic focus ablation,among other procedures.

One variation of a tissue access and imaging apparatus is shown in thedetail perspective views of FIGS. 1A to 1C. As shown in FIG. 1A, tissueimaging and manipulation assembly 10 may be delivered intravascularlythrough the patient's body in a low-profile configuration via a deliverycatheter or sheath 14. In the case of treating tissue, it is generallydesirable to enter or access the left atrium while minimizing trauma tothe patient. To non-operatively effect such access, one conventionalapproach involves puncturing the intra-atrial septum from the rightatrial chamber to the left atrial chamber in a procedure commonly calleda transseptal procedure or septostomy. For procedures such aspercutaneous valve repair and replacement, transseptal access to theleft atrial chamber of the heart may allow for larger devices to beintroduced into the venous system than can generally be introducedpercutaneously into the arterial system.

When the imaging and manipulation assembly 10 is ready to be utilizedfor imaging tissue, imaging hood 12 may be advanced relative to catheter14 and deployed from a distal opening of catheter 14, as shown by thearrow. Upon deployment, imaging hood 12 may be unconstrained to expandor open into a deployed imaging configuration, as shown in FIG. 1B.Imaging hood 12 may be fabricated from a variety of pliable orconformable biocompatible material including but not limited to, e.g.,polymeric, plastic, or woven materials. One example of a woven materialis Kevlar® (E. I. du Pont de Nemours, Wilmington, Del.), which is anaramid and which can be made into thin, e.g., less than 0.001 in.,materials which maintain enough integrity for such applicationsdescribed herein. Moreover, the imaging hood 12 may be fabricated from atranslucent or opaque material and in a variety of different colors tooptimize or attenuate any reflected lighting from surrounding fluids orstructures, i.e., anatomical or mechanical structures or instruments. Ineither case, imaging hood 12 may be fabricated into a uniform structureor a scaffold-supported structure, in which case a scaffold made of ashape memory alloy, such as Nitinol, or a spring steel, or plastic,etc., may be fabricated and covered with the polymeric, plastic, orwoven material. Hence, imaging hood 12 may comprise any of a widevariety of barriers or membrane structures, as may generally be used tolocalize displacement of blood or the like from a selected volume of abody lumen or heart chamber. In exemplary embodiments, a volume withinan inner surface 13 of imaging hood 12 will be significantly less than avolume of the hood 12 between inner surface 13 and outer surface 11.

Imaging hood 12 may be attached at interface 24 to a deployment catheter16 which may be translated independently of deployment catheter orsheath 14. Attachment of interface 24 may be accomplished through anynumber of conventional methods. Deployment catheter 16 may define afluid delivery lumen 18 as well as an imaging lumen 20 within which anoptical imaging fiber or assembly may be disposed for imaging tissue.When deployed, imaging hood 12 may expand into any number of shapes,e.g., cylindrical, conical as shown, semi-spherical, etc., provided thatan open area or field 26 is defined by imaging hood 12. The open area 26is the area within which the tissue region of interest may be imaged.Imaging hood 12 may also define an atraumatic contact lip or edge 22 forplacement or abutment against the tissue region of interest. Moreover,the diameter of imaging hood 12 at its maximum fully deployed diameter,e.g., at contact lip or edge 22, is typically greater relative to adiameter of the deployment catheter 16 (although a diameter of contactlip or edge 22 may be made to have a smaller or equal diameter ofdeployment catheter 16). For instance, the contact edge diameter mayrange anywhere from 1 to 5 times (or even greater, as practicable) adiameter of deployment catheter 16. FIG. 1C shows an end view of theimaging hood 12 in its deployed configuration. Also shown are thecontact lip or edge 22 and fluid delivery lumen 18 and imaging lumen 20.

As seen in the example of FIGS. 2A and 2D, deployment catheter 16 may bemanipulated to position deployed imaging hood 12 against or near theunderlying tissue region of interest to be imaged, in this example aportion of annulus A of mitral valve MV within the left atrial chamber.As the surrounding blood 30 flows around imaging hood 12 and within openarea 26 defined within imaging hood 12, as seen in FIG. 2A, theunderlying annulus A is obstructed by the opaque blood 30 and isdifficult to view through the imaging lumen 20. The translucent fluid28, such as saline, may then be pumped through fluid delivery lumen 18,intermittently or continuously, until the blood 30 is at leastpartially, and preferably completely, displaced from within open area 26by fluid 28, as shown in FIG. 2B.

Although contact edge 22 need not directly contact the underlyingtissue, it is at least preferably brought into close proximity to thetissue such that the flow of clear fluid 28 from open area 26 may bemaintained to inhibit significant backflow of blood 30 back into openarea 26. Contact edge 22 may also be made of a soft elastomeric materialsuch as certain soft grades of silicone or polyurethane, as typicallyknown, to help contact edge 22 conform to an uneven or rough underlyinganatomical tissue surface. Once the blood 30 has been displaced fromimaging hood 12, an image may then be viewed of the underlying tissuethrough the clear fluid 30. This image may then be recorded or availablefor real-time viewing for performing a therapeutic procedure. Thepositive flow of fluid 28 may be maintained continuously to provide forclear viewing of the underlying tissue. Alternatively, the fluid 28 maybe pumped temporarily or sporadically only until a clear view of thetissue is available to be imaged and recorded, at which point the fluidflow 28 may cease and blood 30 may be allowed to seep or flow back intoimaging hood 12. This process may be repeated a number of times at thesame tissue region or at multiple tissue regions.

FIG. 3A shows a partial cross-sectional view of an example where one ormore optical fiber bundles 32 may be positioned within the catheter andwithin imaging hood 12 to provide direct in-line imaging of the openarea within hood 12. FIG. 3B shows another example where an imagingelement 34 (e.g., CCD or CMOS electronic imager) may be placed along aninterior surface of imaging hood 12 to provide imaging of the open areasuch that the imaging element 34 is off-axis relative to a longitudinalaxis of the hood 12, as described in further detail below. The off-axisposition of element 34 may provide for direct visualization anduninhibited access by instruments from the catheter to the underlyingtissue during treatment.

In utilizing the imaging hood 12 in any one of the procedures describedherein, the hood 12 may have an open field which is uncovered and clearto provide direct tissue contact between the hood interior and theunderlying tissue to effect any number of treatments upon the tissue, asdescribed above. Yet in additional variations, imaging hood 12 mayutilize other configurations. An additional variation of the imaginghood 12 is shown in the perspective and end views, respectively, ofFIGS. 4A and 4B, where imaging hood 12 includes at least one layer of atransparent elastomeric membrane 40 over the distal opening of hood 12.An aperture 42 having a diameter which is less than a diameter of theouter lip of imaging hood 12 may be defined over the center of membrane40 where a longitudinal axis of the hood intersects the membrane suchthat the interior of hood 12 remains open and in fluid communicationwith the environment external to hood 12. Furthermore, aperture 42 maybe sized, e.g., between 1 to 2 mm or more in diameter and membrane 40can be made from any number of transparent elastomers such as silicone,polyurethane, latex, etc. such that contacted tissue may also bevisualized through membrane 40 as well as through aperture 42.

Aperture 42 may function generally as a restricting passageway to reducethe rate of fluid out-flow from the hood 12 when the interior of thehood 12 is infused with the clear fluid through which underlying tissueregions may be visualized. Aside from restricting out-flow of clearfluid from within hood 12, aperture 42 may also restrict externalsurrounding fluids from entering hood 12 too rapidly. The reduction inthe rate of fluid out-flow from the hood and blood in-flow into the hoodmay improve visualization conditions as hood 12 may be more readilyfilled with transparent fluid rather than being filled by opaque bloodwhich may obstruct direct visualization by the visualizationinstallments.

Moreover, aperture 42 may be aligned with catheter 16 such that anyinstallments (e.g., piercing instruments, guidewires, tissue engagers,etc.) that are advanced into the hood interior may directly access theunderlying tissue uninhibited or unrestricted for treatment throughaperture 42. In other variations wherein aperture 42 may not be alignedwith catheter 16, installments passed through catheter 16 may stillaccess the underlying tissue by simply piercing through membrane 40.

In an additional variation, FIGS. 5A and 5B show perspective and endviews, respectively, of imaging hood 12 which includes membrane 40 withaperture 42 defined therethrough, as described above. This variationincludes a plurality of additional openings 44 defined over membrane 40surrounding aperture 42. Additional openings 44 may be uniformly sized,e.g., each less than 1 mm in diameter, to allow for the out-flow of thetranslucent fluid therethrough when in contact against the tissuesurface. Moreover, although openings 44 are illustrated as uniform insize, the openings may be varied in size and their placement may also benon-uniform or random over membrane 40 rather than uniformly positionedabout aperture 42 in FIG. 5B. Furthermore, there are eight openings 44shown in the figures although fewer than eight or more than eightopenings 44 may also be utilized over membrane 40.

Additional details of tissue imaging and manipulation systems andmethods which may be utilized with apparatus and methods describedherein are further described, for example, in U.S. patent applicationSer. No. 11/259,498 filed Oct. 25, 2005 (U.S. Pat. Pub. 2006/0184048A1), which is incorporated herein by reference in its entirety.

In utilizing the devices and methods above, various procedures may beaccomplished. One example of such a procedure is crossing a tissueregion such as in a transseptal procedure where a septal wall is piercedand traversed, e.g., crossing from a right atrial chamber to a leftatrial chamber in a heart of a subject. Generally, in piercing andtraversing a septal wall, the visualization and treatment devicesdescribed herein may be utilized for visualizing the tissue region to bepierced as well as monitoring the piercing and access through thetissue. Details of transseptal visualization catheters and methods fortransseptal access which may be utilized with the apparatus and methodsdescribed herein are described in U.S. patent application Ser. No.11/763,399 filed Jun. 14, 2007 (U.S. Pat. Pub. 2007/0293724 A1), whichis incorporated herein by reference in its entirety. Additionally,details of tissue visualization and manipulation catheter which may beutilized with apparatus and methods described herein are described inU.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005 (U.S.Pat. Pub. 2006/0184048 A1), which is incorporated herein by reference inits entirety.

FIG. 6 illustrates one example of a system configured to enable directvisualization of tissue underlying hood 12 and optionally tissuetreatment, e.g., ablation. As shown in ablation assembly 50, hood 12 anddeployment catheter 16 are coupled to handle 52, as previouslydescribed. Fluid reservoir 56, shown in this example as a saline-filledbag reservoir, may be attached through handle 52 to provide the clearingfluid and/or ablation medium. An optional access cannula 54 is alsoillustrated attached to handle 52 and may be used in one variation as anaccess lumen for flushing or clearing a working channel through handle52 and catheter 16 where such a working channel may be used to introduceand advance any number of instruments for tissue treatment, e.g., anaccess needle which may be advanced into handle 52 and into or throughhood 12. An optical imaging assembly 58 coupled to an imaging elementpositioned within or adjacent to hood 12 may extend proximally throughhandle 52 and be coupled to imaging processor assembly 60 (which mayalso optionally include a light source) for processing the imagesdetected within hood 12. Assembly may also be coupled to a videoreceiving assembly 62 for receiving images from the optical imagingassembly 58. The video receiving assembly 62 may in turn be coupled tovideo processor assembly 64 which may process the detected images withinhood 12 for display upon video display 68.

FIGS. 7A and 7B show a side view of a variation of the catheter controlhandle assembly and a detail side view of the handle 52 having acatheter steering and locking assembly 70 integrated along the handle52. As shown, handle 52 may have several access channels defined throughwhich allow for communication for any number of instruments into and/orthrough the catheter 16 and hood 12. For instance, a fluid catheter 86may be positioned at least partially through fluid channel 88 withinhandle 52. The optical imaging assembly 58, e.g., a fiberscope or CCD orCMOS imaging assembly, maybe positioned through support shaft 94 andsupport shaft interface 96 which enters handle 52. In the case where afiberscope is utilized, the fiberscope shaft 82 may be passed through anoptional optical adjustment assembly 84, as described in further detailbelow. Another working channel 80 may be further defined through handle52 to allow for entry and passage of yet another instrument, e.g., apiercing needle, ablation probe, etc.

Also shown is catheter steering and locking assembly 70 integrated alongthe handle 52 having a steering member 72 pivotably coupled to a lockingmember 74. Steering member 72 may be coupled to one or more pullwires 78attached thereto via retaining member 92, e.g., set screw, such thatmanipulation of the steering member articulates the steerable sectionand hood in a corresponding manner. Steering member 72 may be pivotablycoupled to locking member 74 along a point of rotation and lockingmechanism 76 which is attached to a steering plate 90.

The catheter shaft contains at least one lumen which allows the passageof one or more pullwires that are connected to the steering member 72 atthe proximal end of the pullwire while the distal end may be terminatedand anchored to the steering mechanisms along the steerable portion 100of the catheter 16. Details of steering mechanisms and steerablesections of the visualization catheter, which may be utilized withapparatus and methods described herein are described in U.S. patentapplication Ser. No. 12/108,812 filed Apr. 24, 2008 and Ser. No.12/117,655 filed May 8, 2008, each of which is incorporated herein byreference in its entirety. The one or more pullwires can be made frommetal such as stainless steel or nitinol. A compression coil, e.g., madeof stainless steel, with a slightly larger diameter than the pullwiremay be positioned about the pullwire within the handle 52 to allow thepullwire to slide freely therethrough. The ends of the compression coilmay be glue jointed to the proximal end to the catheter body and thedistal end to the side wall of the shaft. Alternatively, the pullwiremay be passed through a hypo tube made of stainless steel and beanchored at the distal side wall of the catheter 16.

In use, steering member 72 may be actuated, e.g., by pulling the memberproximally, to articulate the steerable portion 100 and hood 12 in thesame direction of articulation 102, as shown in the side view of FIG.8A. With the steerable portion 100 articulated to the degree desired toposition hood 12, locking member 74 may be actuated, e.g., in thedirection of locking 104, to maintain a configuration of steerableportion 100 and hood 12 by preventing or inhibiting movement of steeringmember 72, as shown in the side view of FIG. 8B, thus freeing the handor hands of the user. A steering indicator 106 and/or locking indicator108 may be optionally incorporated along handle 52 as a reminder to theuser.

FIG. 9 illustrates a perspective view of an exploded steering andlocking assembly. As shown, the locking member 74 may define an opening112 which is keyed to locking mechanism 76, e.g., lock hex nut, suchthat the locking mechanism 76 rotates when locking member 74 is rotated.Locking mechanism 76 may also pass through an opening 114 defined alongthe steering member 72 as well as through an opening 116 defined throughthe steering plate 90 such that a terminal end of the locking mechanism76 is coupled to lock bolt 118. Once the one or more pullwires, whichmay be secured within pullwire passage 120 defined through the steeringmember 72 by set screw 92, is pulled to a desired degree by steeringmember 72, locking member 74 may be rotated about axis of rotation 110to drive locking mechanism 76 into the lock bolt 118 to compress thesteering member 72 between the steering plate 90 and the locking member74. Hence, steering member 72 is locked in its current position whenlocking member 74 is applied thereby holding the steerable section inits desired configuration.

As previously mentioned, the handle assembly may also optionallyincorporate an optical adjustment assembly 84, as shown in theperspective exploded assembly view of FIG. 10A. The optical adjustmentassembly 84 may be used to move the distal lens of a visualizationinstrument, such as a fiberscope, distally or proximally from the imagedtissue region, hence simulating a zoom-in and/or zoom-out opticaleffect. Generally, the optical adjustment assembly 84 is able to providezoom-in and/or zoom-out capabilities by varying the length of theassembly. As depicted in the cross-sectional side views of FIGS. 10B andIOC, an adjustment member 130 houses guide shaft 134 which extendsproximally through receiving channel 132 of adjustment member 130 and isretained within by a retaining lip 136. The proximally extending slidingshaft portion 144 of a second shaft is positioned slidably within guideshaft 134 while the distally extending distal shaft portion 142 of thissecond shaft is positioned within a sleeve opening 152 of retainingsleeve 150, which is also positioned within adjustment member 130. Thissecond shaft further comprises a threaded guide 146 along a portion ofits outer surface which is configured to engage rotatably with the innersurface of sleeve opening 152, which is also threaded in a complementarymanner.

With the shafts assembled, one or more fasteners 158, e.g., set screw,may be used to secure adjustment member 130 to retaining sleeve 150through fastener opening 156 defined through member 130 and fastenerinterface 154 defined along retaining sleeve 150. Distally extendingdistal shaft portion 142 may further define connector interface 148 forcoupling to a retaining luer connector 160 while guide shaft 134 mayalso define a connector interface 138 for coupling to a luer connector140. In use, the shaft of a visualization instrument such as afiberscope may be positioned through and secured to the assembly 84 byone or more of the connectors, e.g., luer connector 160. By rotatingadjustment member 130, which is coupled to retaining sleeve 150, distalshaft portion 142 may be advanced or retracted relative to guide shaft134 via the threaded engagement between threaded guide 146 and sleeveopening 152. The assembly 84 may be accordingly varied in length whiledistally or proximally advancing the fiberscope based on the variedlength of the optical adjustment assembly 84 to control the visualizedfield of view.

Also previously mentioned above, the optical imaging assembly 58 may beoptionally positioned through a support shaft 94 and support shaftinterface 96 which enters handle 52, as shown in the perspective view ofFIG. 11. Support shaft 94 may be longitudinally reinforced to protectthe optical fiber used by the visualization catheter from buckling orbreaking. To maintain a position of shaft 94 relative to the handle intowhich the shaft 94 extends, shaft 94 may incorporate a strain reliefwire 162 which protrudes from the distal end of shaft 94 at an angle fortemporarily locking within a wire channel 164, as shown above in FIG.7B. Once wire 162 has been engaged within channel 164 within the handle,shaft 94 may provide stability to the fiberscope shaft. The wire 162 canbe made from stainless steel or nitinol and have a thickness between,e.g., 0.050″ to 0.100″.

Because manipulation of the hood 12 and steerable portion correspondswith an angle at which the handle is positioned, handle 52 may alsoserve as an orientation indicator for the hood 12 and steerable portiononce the hood 12 has been introduced into the patient's body. As shownin the side view of FIG. 12, the handle 52 may define a plane A.Articulation of hood 12 and the steerable portion may thus also define aplane A′ which corresponds planarly to the plane A defined by the handle52. This correspondence between the planes A, A′ of the handle 52 andthe resulting articulation of the hood 12 and steerable portion may beparticularly useful for efficiently controlling the hood position withinthe patient's body. As the catheter 16 is usually repeatedly torquedduring a procedure, keeping track of the orientation of the deflectionof the hood 12 can be difficult, if not impossible, unless fluoroscopyis used. With the handle 52, the angle of deflection of the hood 12 canbe predicted by the operator without the need of fluoroscopy. This iscan be particularly desirable in procedures such as transseptalpunctures where an accurate angle of puncture of the septal wall isdesirable to avoid complications such as perforation of the aorta.

An example of how this feature may be utilized is shown in theillustrations of FIGS. 13A and 13B, which show a hood positioned withinthe right atrium of a heart H while coupled to handle 52 positionedexternal to the body. Handle 52 may be seen as being positioned alongplane A while hood 12 and the distal portion of catheter 16 ispositioned within corresponding plane A′. As handle 52 is rotated, e.g.,at 90°, about its longitudinal axis in a direction of rotation 170 suchthat handle 52 then lies within a different plane B, hood 12 and thedistal steerable portion may also rotate, e.g., at 90°, within the rightatrium in a corresponding direction of rotation 170′ such that the hoodand catheter then define a corresponding different plane B′. Thus, bymerely articulating the handle 52 external to the body in a specifieddirection, the user may adjust or desirably position or re-position thehood within the body in a known direction without having to utilizeadditional catheter positioning mechanisms.

FIG. 14 shows an assembly view of another variation of a steering handleassembly 180 which enables a user to steer the visualization hood 12along at least four or more degrees of freedom relative to alongitudinal axis of the catheter 16. FIG. 15 shows a side view of thehandle assembly 180 illustrating handle portion 182 and steering ring184 which may be manipulated along any number of directions relative tohousing 186 to control the articulation of the hood 12. As shown in FIG.16, manipulating or pulling along a portion of steering ring 184, e.g.,along a direction of actuation 192, causes steerable portion 100 andhood 12 to move along a corresponding direction of articulation 194.Moreover, because of die manner in which steering ring 184 is positionedto encircle the handle assembly 180, the operator may grip the handle180 along any orientation and operate the handle assembly 180 with asingle hand 190. For instance, the operator may manipulate the steeringring with the thumb and/or index finger while insertion length of thecatheter 16 can also be simultaneously controlled by the same hand 190by pulling or pushing the handle assembly 180 to translate the entirecatheter 16.

As shown in the cross-sectional side views of FIGS. 17A and 17B, handleassembly 180 may generally comprise a ball pivot 200 supported by pivotsupport 202 enclosed within housing 186. Ball pivot 200 may support thesteering ring 184 via one or more steering ring support members 204,206, e.g., four steering ring support members, which extend radiallythrough corresponding support member openings 208, 210. Because of theball pivot 200 shape, steering ring 184 may be moved about pivot 200 inany number of directions. The terminal ends of one or more pullwires220, 222 may be coupled steering ring 184 via corresponding fasteners212, 214, e.g., set screws, securing each of the pullwire terminationcrimps 216, 218. These pullwires 220, 222 may extend through pivotsupport housing 224 which defines receiving channel 226, which supportspivot support 202, and through pullwire transition manifold 228 and intoa proximal end of a multi-lumen shaft 234, such as catheter 16. Thepullwires may continue distally through catheter 16 where they arecoupled to the steerable portion of catheter 16. Each of the pullwiresmay be optionally encased in corresponding compression coils 230, 232between the transition manifold 228 and catheter.

Although multiple pullwires may be utilized depending upon the number ofdirections for articulation, four pullwires may be typically utilized.Each of the four pullwires may be terminated symmetrically around acircumference of steering ring 184 such that a balanced four-waysteering of the distal portion may be accomplished, althoughmanipulating the steering ring 184 along various portions of itscircumference may yield combinational articulation between the pullwiresto result in numerous catheter configurations. Additionally, the handleassembly may further incorporate a spring mechanism 236 as an overdriveprevention mechanism, as shown in FIG. 17B. Spring mechanism 236 may bepositioned between the transition manifold 228 and ball pivot 200 inorder to prevent over-tensioning or breaking of the pullwires if thesteering ring 184 is over-deflected in a direction.

FIGS. 18A to 18C illustrate side views of the handle assembly 180 andcatheter 16 to show how the hood 12 can be consistently deflected in thesame direction by which the steering ring 184 is being deflectedregardless of the orientation of the handle assembly 180. For example,handle assembly 180 may be deflected in a direction of actuation 240such that hood 12 is deflected in a corresponding direction ofarticulation 242. A first side indicator X of handle 180 and a secondopposing side indicator Y of handle 180 are shown to indicate a firstposition of handle 180 and the corresponding first side indicator X′ ofhood 12 and corresponding second opposing side indicator Y′ of hood 12are likewise shown to indicate a first position of hood 12. The handleassembly 180, catheter 16, and hood 12 are then rotated along anarbitrary direction of rotation 244 about longitudinal axis 246 of theassembly such that the handle positional indicators X, Y and the hoodpositional indicators X′, Y′ are now positioned in opposite locations.Even with the entire assembly rotated, e.g., 180°, actuating thesteering ring 184 along the direction of actuation 248 still results ina corresponding direction of articulation 250 of hood 12 which matchesthe initial direction of articulation 242 despite the rotated assembly.Regardless of the angle by which the operator subsequently rotates thecatheter 16 about the longitudinal axis 246, the operator can still becertain that deflecting the steering ring 184 in a particular directionwill steer the distal end of the catheter in the same direction. Thisremoves the need for the operator to memorize the original position ofthe catheter or how much the catheter has been torqued in order to gaugethe orientation of the deflected end when the catheter is inserted intothe patient.

In yet another variation of the catheter control handle, FIG. 19 showsan assembly view of steering handle assembly 260 which is configured toarticulate a catheter 16 having at least two independently deflectableportions, e.g., a proximal steerable section 262 adapted to articulatewithin a single plane relative to a longitudinal axis of the catheterand a distal steerable section 264 adapted to articulate within one ormore planes relative to a longitudinal axis of the proximal steerablesection 262. Utilizing such catheter steering may be particularlyadvantageous for tissue treatment, e.g., ablation, in the left atrium ofthe heart as such adaptability in steering may impart additionalaccuracy and efficiency to steer the imaging and ablation hood 12 aroundcomplex anatomical structures, such as the pulmonary vein ostium.Examples of such steerable catheters are shown and described in furtherdetail in U.S. patent application Ser. No. 12/108,812 filed Apr. 24,2008 (U.S. Pat. Pub. 2008/0275300 A1) and Ser. No. 12/117,655 filed May8, 2008 (U.S. Pat. Pub. 2008/0281293 A1), each of which is incorporatedherein by reference in its entirety.

Moreover, this handle variation as well as any of the other handlevariations herein may incorporate any of the features described in eachof the variations, as practicable. For instance, this particularvariation may also utilize the optical adjustment assembly, lockingmechanisms, etc. in combination if so desired.

FIGS. 20A and 20B show side views of the steering handle assembly 260with the catheter 16 having proximal steerable section 262 and distalsteerable section 264 extending from distal handle portion 274. As withprevious variations, a steering ring 270 may encircle housing 272.However, this variation further includes a proximal handle portion 276extending from housing 272 with a proximal section control 278 forarticulating proximal steerable section 262. FIGS. 21A and 21B show endviews of the control handle 260 from the perspective of the cathetershaft 16 and from the handle end, respectively. As shown, steering ring270 may be supported by a number of steering ring support members 280,282, 284, 286 which extend from housing 272 through correspondingsupport member openings 288, 290, 282, 294. FIGS. 22A and 22B showadditional perspective assembly and detail views, respectively, of thevisualization assembly and steering handle assembly 260.

As previously described for other variations, this particular handleassembly 260 may be used to control articulation of the hood 12 and thedistal steerable section 264 but also used to further controlarticulation of the proximal steerable section 262. As shown in theperspective view of FIG. 23A, proximal section control 278 may beactuated, e.g., by rotating the control 278 in a first direction 300, toarticulate the proximal steerable section 262 within a first plane,e.g., to retroflex hood 12 and distal steerable section 264 in acorresponding direction of articulation 302. Hood 12 may be furtherarticulated by manipulating steering ring 270, e.g., in a direction ofactuation 304, such that distal steerable section 264 moves in acorresponding direction of articulation 306, as shown in FIG. 23B. Inone variation, proximal steerable section 262 may be configured toarticulate via proximal section control 278 within a single plane whiledistal steerable section 264 may be configured to articulate in at leastfour directions, as above. However, both the proximal section control278 and the steering ring 270 can be manipulated in varying degrees tosteer the respective steerable sections to varying curvatures as desiredby the operator.

FIG. 24 shows a perspective exploded assembly view of the handleassembly 260 while FIG. 25 shows a cross-sectional side view of the samehandle assembled. As shown, a ball pivot 310 having a pivot support 312may be supported within a proximal portion of distal handle portion 274.One or more steering ring support members 314 may extend throughrespective openings defined through housing 272 to support thecircumferentially encircling steering ring 270. As above, a pullwiretransition manifold 316 may be positioned proximal to the catheter 16entrance.

A guide shaft 322 may be positioned at least partially through proximalhandle portion 276 while maintained in position by retaining lip 324. Asliding shaft portion 328 may be positioned slidably within guide shaft322 while a distal shaft portion 326 may extend distally through housing272. A pullwire retaining member 318 haying a pullwire termination crimp320 may be positioned along a distal end of distal shaft portion 326such that as distal shaft portion 326 is translated distally and/orproximally according to the manipulation of section control 278, thepullwire for the proximal steerable section 262 may be accordinglypulled or pushed. The distal shaft portion 326 may further have athreaded guide 330 which is engaged to a threaded inner surface ofretaining sleeve 332, which is secured to section control 278. Thus, ascontrol 278 is rotated, retaining sleeve 332 is also rotated therebyurging distal shaft portion 326 and sliding shaft portion 328 to moveaccordingly via the engagement with threaded guide 330. A further accesslumen 334 is illustrated as extending through the handle assembly 260.

As further illustrated in the cross-sectional side view of FIG. 26, theone or more proximal steerable section pullwire 342 is shown asextending from catheter 16 and extending through transition manifold 316and terminated at pullwire retaining member 318. Additionally, one ormore distal steerable section pullwires 338, 340 are also shown toemerge from catheter 16, through one or more corresponding compressioncoils 336, and through transition manifold 316 to terminate atcorresponding pullwire termination crimps 348, 350, which may be securedto steering ring 270 via fasteners 344, 346, e.g., set screws. Thedistal ends these pullwires, e.g., at least four pullwires, can beanchored to the inner walls of the distal steerable section 264. At boththe proximal as well as the distal ends, the pullwires may be separated,e.g., by 90°, such that the four-way steerable section is able to besteered symmetrically in at least four directions.

The ends of the compression coils 336 may be glue jointed to theproximal end to the catheter body 16 and distally into the transitionmanifold 316. Alternatively, the pullwires may also be passed throughhypodermic tubes and anchored at the distal side wall of the cathetershaft 16 and the transition manifold 316. Moreover, the pullwires may bemade from materials such as stainless steel or nitinol and flexible thinwall compression coils, such as stainless steel coils, may be furtherslid over each pullwire along the catheter shaft 16.

Because of the design of the handle assembly 260 and the accessibilityof the steering ring 270 to the user, the user may utilize a single handto operate the handle assembly 260 to control and manipulate thecatheter 16 and hood 12 configuration and position within the patient'sbody. Moreover, the operator may utilize either their right hand 360,e.g., by gripping handle portion 276, or their left hand 362, e.g., bygripping distal handle portion 274, as shown respectively in FIGS. 27Aand 27B.

As previously described, because the catheter 16 and hood 12 may berepeatedly torqued and repositioned within the patient's body during aprocedure, keeping track of the orientation of the deflection of thehood 12 can be difficult, if not impossible, unless fluoroscopy is used.As the handle assembly 260 provides an indication, as described herein,as to which direction the catheter and hood may be configured based uponthe handle orientation, an orientation guide 372 may be imprinteddirectly upon the handle 274, as shown in detail view 370 of FIG. 28.The plane within which the orientation guide 372 lies may be configuredto be parallel to the plane within which the proximal steerable section262 articulates when section control 278 is manipulated such that theoperator may be able to predict how the catheter 16 will configure whenmanipulated.

As similarly described above, FIGS. 29A and 29B illustrate a hoodpositioned within the right atrium of a heart H while coupled to handleassembly 260 positioned external to the body. Handle assembly 260 may beseen as being positioned along plane A while hood 12 and the distalportion of catheter 16 is positioned within corresponding plane A′. Ashandle assembly 260 is rotated, e.g., at 90°, about its longitudinalaxis in a direction of rotation 380 such that handle assembly 260 thenlies within a different plane B, hood 12 and the distal steerableportion may also rotate, e.g., at 90°, within the right atrium in acorresponding direction of rotation 380′ such that the hood and catheterthen define a corresponding different plane B′. Thus, by merelyarticulating the handle assembly 260 external to the body in a specifieddirection, the user may adjust or desirably position or re-position thehood within the body in a known direction without having to utilizeadditional catheter positioning mechanisms.

Additionally and/or alternatively, visual indicators positioned directlyupon the hood 12 may also be utilized in coordination with correspondingvisual indicators positioned upon the handle itself. The hood 12 mayhave one or more visual indicators marked upon the distal portion of thehood such that the visual image 390 through the hood may show at least afirst directional indicator 392′ along a first portion of the hood, asshown in FIG. 30A. In this example, a second directional indicator 394′and yet a third corresponding third indicator 396′ may be positionedabout a circumference of the hood or hood membrane to represent anynumber of directions. Handle assembly 260 may thus have one or moredirectional indicators located directly upon, e.g., steering ring 270,which correspond spatially with the indicators positioned upon the hoodor hood membrane, as shown in FIG. 30B. For instance, first directionalindicator 392′ on the hood may correspond spatially with firstdirectional indicator 392 on steering ring 270, second directionalindicator 394 on the hood may correspond spatially with seconddirectional indicator 394′ on steering ring 270, third directionalindicator 396 on the hood may correspond with third directionalindicator 396′ on steering ring 270, and so on. Although threedirectional indicators are shown in this example, fewer than three ormore than three may be utilized. Moreover, the location and positioningof the indicators may also be varied, as desired.

In use, the directional indicators as viewed through the hood correspondto the direction the hood may move when the steering ring 270 isdeflected along the position where the corresponding indicator islocated. Thus, deflecting steering ring 270 in direction of actuation398, e.g., along directional indicator 394, may articulate distalsteerable section 264 and hood 12 in a corresponding direction ofarticulation 400 along the directional indicator 394′ shown on the hoodor hood membrane, as shown in FIG. 30C. This removes complexity insteering the hood 12, e.g., when the hood 12 is in a retroflexedposition, where directions are reversed with respect to the operator.

The catheter control systems described herein may additionally integrateany number of features and controls for facilitate procedures. Thesefeatures and controls may be integrated into any of the variationsdescribed herein. FIG. 31 shows one example where features such as flowrate control, air bubble detection, ablation activation switches,built-in image sensors, etc., may be incorporated into the handleassembly.

As shown on handle 52, a flow control 410 switch may be incorporatedwhich may optionally have a high-flow position 412, a no-flow position414, and an optional suction position 416 to control the inflow and/oroutflow of the visualization and/or ablation fluid. One or more fluidreservoirs, e.g., a room temperature purging fluid reservoir 422 and/ora chilled purging fluid reservoir 424, may be fluidly coupled to aprocessing unit 418 which may control various parameters, e.g., valves,inflow, suction, RF ablation energy generation, bubble detection, etc.Processing unit 418 may also incorporate a pump 420, e.g., peristalticpump, which may pump or urge the fluids from the reservoir through oneor more coupling lines into and/or out from handle 52. Processing unit418 may also be electrically coupled to handle 52 and may also be ableto process, display and store several data, including total amount ofsaline used for the entire procedure, power and duration of ablation,impedance of tissue in contact-with hood, rate of flow of saline,temperature of saline, and time of detection of air bubbles during theprocedure.

In the event that handle 52 is used to suction or evacuate fluids outfrom the body, an additional evacuation reservoir 426 may also befluidly coupled to handle 52. Additionally, one or more hemostasisvalves 428 may also be integrated directly upon handle 52. Moreover, animaging sensor 430 which may also incorporate a light source, e.g.,LEDs, and power supply, may additionally be integrated directly intohandle 52. A video cable may be connected to the proximal end of thehandle 52 and can be directly plugged into any standard video displaymonitors (such as ones accepting S-Video, DVI, VGA, RCA inputs), ratherthan utilizing a separate video processing unit.

As processing unit 418 may incorporate processors for detecting variousphysiological parameters, one or more detection indicators 432, e.g.,for bubble detection, and/or ablation actuation switch 434 may beintegrated directly upon the handle 52 as an indicator to the operator.If air bubbles are detected in the irrigation channel, the detectionindicator 432 may be activated to alert the operator of air bubbles. Asoft alarm may also be triggered to further alert the operator.Additionally, with an ablation actuation switch 434 located directlyupon handle 52, the operator may be able to instantaneously activate orstop ablation energy from being delivered to the target tissue bydepressing switch 434 rather than reaching for a separate ablationgenerator. Details for tissue ablation under direct visualization anddetecting various parameters such as bubble formation are also shown anddescribed in further detail in U.S. patent application Ser. No.12/118,439 filed May 9, 2008 (U.S. Pat. Pub. 2009/0030412 A1 ), which isincorporated herein by reference in its entirety.

Another example of an integrated handle is shown illustratively in FIG.32. In this example, handle 274 may incorporate an imaging systemdirectly into the handle. As illustrated, the images captured by theimager 440 positioned within or along hood 12 may be focused onto anelectronic imaging sensor 444, e.g., CMOS sensor, positioned withinhandle 274. Imaging sensor 444 may deliver the images directly to thevideo processor. A light source 448, e.g., LED light source, may also beplaced within the handle 274 to deliver light through, e.g., an opticalfiber 442 positioned within hood 12, to illuminate the tissue region tobe visualized. At the terminal end of the fiber bundle, a focus lens446, e.g., a combination of spherical lenses, may be positioned proximalto the fiber bundle. An alternative may utilize a GRIN lens which may beused as a simple one piece element which is chromatically aberrationcorrected and polarization preserved to allow for more designflexibility. Moreover, a GRIN lens is typically more economical than thespherical lenses.

The applications of the disclosed invention discussed above are notlimited to certain treatments or regions of the body, but may includeany number of other applications as well. Modification of theabove-described methods and devices for carrying out the invention, andvariations of aspects of the invention that are obvious to those ofskill in the arts are intended to be within the scope of thisdisclosure. Moreover, various combinations of aspects between examplesare also contemplated and are considered to be within the scope of thisdisclosure as well.

1-22. (canceled)
 23. A medical manipulation assembly comprising: anelongated distal steerable portion with a distal working channel(c)Mending through the elongated distal steerable portion; an elongatedproximal steerable portion proximal of the elongated distal steerableportion with a proximal working channel extending through the elongatedproximal steerable portion; a distal steering mechanism operable to bendthe distal steerable portion in response to movement of the distalsteering mechanism; a proximal steering mechanism operable to bend theproximal steerable portion, independently of the distal steerableportion, in response to rotational movement of the proximal steeringmechanism; one or more distal pullwires extending between the elongateddistal steerable portion and the distal steering mechanism; and one ormore proximal pullwires extending between the elongated proximalsteerable portion and the proximal steering mechanism, wherein thedistal and proximal portion working channels are configured to receive avisualization instrument therethrough.
 24. The medical manipulationassembly of claim 23 wherein the distal steering mechanism is operableto bend the distal steerable portion in response to pivoting movement ofthe distal steering mechanism.
 25. The medical manipulation assembly ofclaim 23 further comprising the visualization instrument wherein thevisualization instrument is extendable distally beyond the proximal anddistal steerable portions.
 26. The medical manipulation assembly ofclaim 25 wherein the visualization instrument is a camera.
 27. Themedical manipulation assembly of claim 25 wherein the visualizationinstrument includes a plurality of optical fibers.
 28. The medicalmanipulation assembly of claim 23 wherein at least one of the proximalor distal steering mechanisms is operable by computer control.
 29. Themedical manipulation assembly of claim 23 wherein the distal andproximal working channels are configured tor passage of an irrigationfluid therethrough.
 30. The medical manipulation assembly of claim 23wherein the distal and proximal portion working channels are configuredfor passage of an ablation instrument therethrough.
 31. The medicalmanipulation assembly of claim 23 further comprising a lighting sourceextending within the distal steerable portion.
 32. The medicalmanipulation assembly of claim 23 wherein the one or more proximal anddistal pullwires include a compression coil.
 33. A method performed by acomputing system, the method comprising: moving a distal steeringmechanism to bend an elongated distal steerable portion of a medicalassembly, the distal steerable portion including a distal workingchannel; moving a proximal steering mechanism, independently of themovement of the distal steerable mechanism, to bend an elongatedproximal steerable portion of the medical assembly, the proximalsteerable portion extending proximally of the elongated distal steerableportion and including a proximal working channel; responsive to themovement of the distal steering mechanism, manipulating one or moredistal pullwires extending between the elongated distal steerableportion and the distal steering mechanism to bend the distal steerableportion; and responsive to the movement of the proximal steeringmechanism, manipulating one or more proximal pullwires extending betweenthe elongated proximal steerable portion and the proximal steeringmechanism to bend the proximal steerable portion, wherein the distal andproximal portion working channels are configured to receive avisualization instrument therethrough.
 34. The method of claim 33wherein moving the distal steering mechanism includes pivoting thedistal steering mechanism.
 35. The method of claim 33 further comprisingextending the visualization instrument distally beyond the proximal anddistal steerable portions.
 36. The method of claim 33 wherein thevisualization instrument is a camera.
 37. The method of claim 33 whereinthe visualization instrument includes a plurality of optical fibers. 38.The method of claim 33 further comprising displaying an image obtainedby the visualization instrument.
 39. The method of claim 33 furthercomprising conveying an irrigation fluid through the distal and proximalworking channel.
 40. The method of claim 33 further comprising receivingan ablation instrument through the distal and proximal working channels.41. The method of claim 33 further comprising operating a lightingsource positioned within the distal steerable portion.
 42. The method ofclaim 33 wherein the one or more proximal and distal pullwires include acompression coil.